Mine get cheap, generic dry cat food (30-32% protein) as a snack, especially when they're molting and during the winter. They also get BOSS and leftovers of all kinds from my family's kitchen. I once had the bright idea to mix the cat food and BOSS into their pellets in the feeders but quickly found out that they will toss out all the pellets to get to the dessert. Consequently they get limited amounts tossed in their run so it's not their main source of feed. I"m not selling chickens or eggs as "organic" so I don't worry about whether what I feed them will affect their rating as long as I know they are getting things that are good for them. Oyster shell for calcium is served on the side free-choice in a hanging rabbit feeder bin. I don't worry about grit since they are busily digging up various areas of my yard and eating the contents of their sandbox/dust bin.